In an attempt to learn from what James Surowiecki calls "The Wisdom of Crowds", I asked yesterday on Twitter
what difference a statutory register of lobbyists would have made to
the Patrick Mercer case. The best answer I got was, first, that Mercer
would have checked the register and, second, would have found the
Panorama/Daily Telegraph operation wasn't on it – after which he
presumably would not have been drawn into the sting. So the main
difference a register would have made, according to my interlocutors,
was to protect MPs against investigative journalists – not necessarily a
very happy outcome.

However, it is possible that it wouldn't have made any difference at
all, and certain that it would not do so in the case of an MP determined
to breach the rules and the law. An MP who is prepared to defy both today in a quest for money is unlikely to be deterred by
both tomorrow in the form of a statutory register. (Mercer was in breach of rules on paid
advocacy, and faces a possible police investigation under
the Bribery Act.) Furthermore, the wits of the regulators are unlikely
to be more sharp than those of investigative journalists. As Mark Wallace pointed out, the latter could set up a front company in say, Switzerland – and get on the register that way.

Mark's suggestion will doubtless provoke ever-more ingenious
suggestions for tightening the proposed register further – all the way
to the logical end-point at which all of us are registered as lobbyists
(including you, dear reader: good luck with filling in the form). For that, after all, is what we are in relation to those we elect: we lobby either as part of a group or, more likely, as individual constituents. Do I hear it claimed that separating constituents from lobbyists would be easy? Really? What of the teacher who's a local or national trade union officer, or the business which is locally based but foreign-owned, or the standard e-mail got up by 38 Degrees?

Talking of 38 Degrees, what about all those other special interests – Greenpeace, the Child Poverty Action Group, the RSPCA, the National Institute of Economic and Social Research? Shouldn't they all have to register, too? Those who favour a register will cite that very contemporary idea, transparency. But even if another one – proportionality – is applied, there is good cause to be wary. The big lobbying companies tend to favour a register precisely because they would be likely to get on it – a classic instance of well-established interest groups squeezing out the competition.

If the sacred cause of transparency still floats your boat, so be it. But don't pretend that it would stop Parliamentarians who are determined to behave badly, because it won't. Nothing will. Only Nick Clegg and his fellow Liberal Democrats could possibly believe otherwise. Proposals for a statutory register of lobbyists will provide the political parties with enormous fun. (David Cameron is using the revival of the idea as a means of having a crack at trade union funding.) But if it ever happens, the Daily Telegraph and Panorama's sleazebusters will still be in business afterwards, until the end of Parliament – indeed (who knows?) until the end of time.